Pilot Valve Measurement For Maximum Speed - ABB AV3 Instruction Manual

CALIBRATION
CAUTION
GAIN AND SPEED ADJUSTMENTS
4 - 10
is how the positioner comes from the factory. Use the following
procedure to reduce the speed of operation.
Never adjust the pilot valve for a stroke greater than the
0.030 in either direction. A greater stroke will reduce the
positioner's performance.
STE M IS
F LU S H
W ITH B O DY
ST E M P O S IT IO N AT
B A LA N C E C O N D IT IO N
Figure 4-6. Pilot Valve Measurement for Maximum Speed
1. To reduce the stroke speed, use a
the top adjustment screw clockwise
time (Fig. 4-7). ABB suggests
number of turns. In total, do not exceed one full turn (clockwise)
from the factory setting (Fig. 4-6). This adjustment controls the
amount of air going to port 01.
⁄
2. Use a -inch Allen wrench (the wrench must be at least
3 32
5-inches long). Turn the lower adjustment screw clockwise the
same amount as the top to insure speed of operation is the same
in both directions. Be careful when accessing the lower adjust-
ment screw. Insert the Allen wrench up through the bottom of the
range spring (Fig. 4-7). This adjustment controls the amount of air
going to port 02.
NOTE: A single-acting application only requires one pilot valve
screw adjustment depending on the port connection. The top
adjustment screw affects the 01 port. The bottom adjustment
screw affects the 02 port.
3. Test for satisfactory stroke time and adjust as required.
0 .0 30
0 .03 0
S T E M P O S IT IO N TO P S T E M P O S IT IO N LOW E R
AD JU S TM E N T S C R E W A D JU S TM E N T S C R E W
⁄
-inch Allen wrench. Turn
3 32
⁄
of a turn to reduce stroke
1 8
⁄
-turn increments. Take note of the
1 8
T 00 7 77 A